“Improvisation is like a face lift: if you notice, it’s bad.” John Waters is typically adroit, on-point and witty in this 25-minute conversation with critic J. Hoberman, conducted at Lincoln Center earlier this month on the opening night of the adeptly titled career retrospective “Fifty Years of John Waters: How Much Can You Take?” Topics of discussion include Waters’ influences, filming Divine in prison, and what it’s like to look back at his past provocations.